Gear train resetting mechanism



May 23, 1967 E. D. slGL GEAR TRAIN RESETTING .MECHANISM 5 Sheets-Sheet lOriginal Filed Sept. 18, 1963 INVENTOR. n

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GEAR TRAIN RESETTING MECHANISM s t sh t a Original Filed Sept. 18, 19535 hee S ee Mawfegs May 23, 1967 E. D. SIGL 3,321,134

GEAR TRAIN RESETTING MECHANISM original Filed sept. 18, 1963 v 5Sheets-Sheet 5 X INVENTOR 5c/Wa ra D. S {lg/5 BY www May 23, 1967 E. D.SI'GL 3,321,134

GEAR TRAIN RESETTING MECHANISM- original Filed sept. 18, 1963 5Sheets-Sheet 4 INVENTOR.

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United States Patent O 2li Claims. (Cl. 23S-144) This invention relatesgenerally to mechanisms for returning a gear to a predeterminedrotational position independently of another gear with which it isnormally in mesh, and more particularly to resetting mechanisms forrevolution counters. This application is a continuation of myapplication Ser. No. 309,719, filed Sept. 18, 1963, and now abandoned,

Revolution counters conventionally comprise a plurality of number wheelswith intermittent motion transferring mechanism respectivelyinterconnecting the wheels and advancing each higher order number wheela predetermined incremental amount in response to a predeterminedrotation of the next lower order number wheel. A common form ofintermittent motion transferring mechanism comprises a segmental gear,such as a twotooth gear, and a cooperating locking cam rotatable withthe lower order number wheel, a full-tooth gear rotatable with thehigher order number wheel, and a transfer pinion having a full-toothportion interconnecting the gears and a multilated portion having everyother tooth removed cooperating with the locking cam.

There are applications where it is desirable simultaneously andsubstantially instantaneously to return or reset all of the numberwheels of a revolution counter to a predetermined position, such as azero indication. In order to reset the number wheels, it is necessary todisengage the transfer pinions from their respective segmental andfull-tooth gears prior to resetting of the number wheels to the desiredposition. In conventional `reset counters, the number wheels are resetby means of heart-shaped cams respectively secured to the number wheelsand cooperating operating arms which engage the cams and return the sameto predetermined positions. In such conventional counters, a linkageconnects the o erating arms and the transfer pinions so tha-t during therst part of the resetting stroke of the operating arms the pinions aremoved out of mesh with the gears, during the second part of theresetting stroke the operating arms engage the cams to rotate the numberwheels to the desired position, during the first part of the returnstroke, the operating `arms retract from the heart-shaped cams, andduring the last part of the return stroke, the pinions are moved backinto mesh with the gears; the sequence of operation during a returnstroke of the operating arms is the reverse of the sequence of operationduring the resetting stroke.

With such conventional resetting mechanism, there is an interval duringthe return stroke of the operaing arms following their disengagementfrom the heart-shaped cams and prior to reengagement of the pinions withthe gears during which the number wheels are unrestrained and can rotatedue to the shock of the resetting operation, vibration, or merely due tothe out-of-balance weight of the heart-shaped cams. Such unrestrainedrotation of the number wheels during the resetting operation can resultin an erroneous reading or in failure of the transfer pinions to go backinto mesh with the respective gears. Attempts have been made to providea restraint upon the number wheels during the last half of the resettingoperation in order to .prevent such rotation, however, such efforts havegenerally involved the application of friction on the wheels and haveaccordingly increased the driving torque required for normal operation.

It is therefore desirable to provide a resetting mechanism for arevolution counter in which the transfer pinions are 1re-engaged withthe gears prior to retraction of the operating arms, ie., while theheart-shaped cams and number wheels are restrained by the operatingarms, in order to insure that the number wheels remain in properalignment and that the pinions accurately remesh with the respectivegears.

In addition to the requirement for simultaneously and substantiallyinstantaneously resetting all of the number wheels of one counter to apredetermined position, there are instances where it is requiredsimultaneous and substantially instantaneously to reset a number ofrevolution counters each having a plurality of number wheels. In priorresetting mechanisms known to the present applicant, the operating armswere in the form of pivotally mounted levers having their ends engagingand in effect pushing the heart-shaped cams to the desired position, theend of the lever engaging the low or dwell portion of the cam at itsreset position. By virtue of the eccentric configuration of theheart-shaped cams, the longest lever arm and thus the greatestmechanical advantage is provided when the heart-shaped cam is rotated byfrom its reset position, this lever arm and thus the mechanicaladvantage decreasing as the cam is rotated and becoming very small asthe cam approaches its reset position. Thus, the force required for theresetting operation increases rapidly as the cams approach their resetpositions, and substantial force is required in instances where it isnecessary simultaneously to reset a bank of counters. It is thereforefurther desirable to provide a resetting mechanism for revolutioncounters wherein less torque is required adjacent the end of theresetting stroke than has hereeofore been necessary with conventionalresetting mechanisms.

It is accordingly an object of the invention to provide improvedmechanism for `returning a gear to a predetermined rotational positionindependently of another gear normally in mesh therewith.

Another object of the invention is to provide an improved resettingmechanism for revolution counters.

A further object of the invention is to provide an improved resettingmechanism for revolution counters wherein proper alignment of the numberwheels and aecurate remeshing of the transfer pinions with therespective gears is provided.

A still further object of the invention is to provide an improvedresetting mechanism for revolution counters of the type employingheart-shaped cams and operating arms for rotating the same topredetermined positions wherein the transfer pinions are re-engaged withthe respective gears prior to disengagement of the operating arms fromthe heart-shaped cams.

Yet another object of the invention is to provide improved resettingmechanism for counters wherein less torque is required adjacent the endof the resetting stroke than has previously been necessary.

Further objects and advantages will become apparent by reference to thefollowing description and the accompanying drawings, and the features ofnovelty which characterize my invention will be pointed out withparticularity in the claims annexed to and forming a part of thisspecification.

In accordance with the broader aspects of the invention, mechanism isprovided for returning a first gear of a gear train to a predeterminedrotational position from another position rotationally spaced therefromindependently of a second gear which is normally in mesh with the firstgear. Cam means is connected to the first gear, is rotatable therewith,and has high and dwell portions, the cam means having a normal positionwhen the first gear is in its predetermined position. An operatingmember is provided movable between first and second positions, theoperating member in its first position being out of engagement with thecam means and in vits second position engaging the dwell portion of thecam means thus moving the cam means to its normal position 1n responseto movement of `the operating member from its first to its secondposition; the cam means remains in its normal position when theoperating member is returned from its second position to its firstposition. Another member is provided for rotatably mounting the secondgear and is movable between a first position with the second gear inmesh with the first gear and a second position with the second gear outof mesh with the first gear. Actuating means are provided for moving theoperating member from its first to its second positions, the actuatingmeans including means for moving the mounting member so as to move thesecond gear out of mesh with the first gear in advance of engagement ofthe operating member with the cam means. The actuating means furtherincludes means for moving the mounting member to its first position whenthe operating member has reached its second lposition and for retainingthe mounting member in its rst position during return of the operatingmember to its first position so that the second gear is moved into meshwith the first gear prior to movement of the operating member out ofengagement with the dwell portion of the cam means.

In accordance with a further aspect of the invention, the operatingmember has a surface which engages the dwell portion when the operatingmember is in its second position, the surface being convexly curved withrespect to the cam means and providing a camming or wedging actiontherewith when the opertaing member approaches the end of its movementfrom its first to its second positions.

In the drawings:

FIG. 1 is a top view of an impulse counter incorporating the invention;

FIG. 2 is a View of one side of the counter of FIG. 1, partly brokenaway, taken along the line 2-2 thereof;

FIG. 3 is a fragmentary view of the other side of the Y counter of FIG.1 taken along the line 3-3;

FIG. 4 is a cross-sectional view taken along the line 4-4 of FIG. l;

FIG. 5 is a fragmentary cross-sectional View taken along the line 5-5 ofFIG. 3;

FIG. 6 is a fragmentary cross-sectional view taken along the line 6-6 ofFIG. 3;

FIG. 7 is a cross-sectional view taken along the line 7--7 of FIG. 6;

FIGS. 8, 9, 10 and 11 are diagrams illustrating the mode of operation ofthe resetting mechanism of the counter of the previous figures;

FIG. 12 is a schematic diagram useful in explaining the operation of theinvention; and

FIGS. 13 and 14 illustrate modifications of the invention.

Referring now to the gures of the drawing, a counter of the impulse typeis shown, i.e., wherein the lowest order number wheel is advanced by onedigit in response to a pulse applied to an actuating coil; in theillustrated embodiment, the lowest order number wheel is advanced byone-half digit when the actuating coil is energized and the remaininghalf digit when the coil is de-energized.

The counter comprises a frame having upstanding ends 22 and 24 connectedby a base portion 36, an actuating coil mounting portion 28, and acrossbar portion 30. In the illustrated embodiment, four progressivelyhigher order number Wheels 32, 34, 36 and 38 are provided rotatablymounted on shaft 40 extending between and journaled in the frame ends22, 24.

A star wheel 42 is mounted on shaft 40 and has a gear 44 connectedthereto. Gear 44 normally meshes with a full-tooth pinion 46 rotatablymounted on pinion shaft 48, pinion 46 normally meshing with gear 50secured to the lowest order number wheel 32. Gears 44, 50 and pinion 46provide a one-to-one driving connection between the star wheel 42 andthe lowest order number wheel 32 and in the illustrated embodiment,gears 44 and 50 are provided with twenty teeth and pinion 46 is providedwith eight teeth. Heart-shaped cam 52 is posi-V tioned between gears 44and 50 and secured to gear 50.

An actuating pawl S4 is provided cooperating with the start wheel 42 toadvance the lowest order number wheel 32. Pawl 54 is pivotally mountedon pivot post 56 extending between the frame ends 22, 24 and has anupstanding portion 518 terminating in yoke portion 60; Transverselyextending portion 62 of the actuating pawl 5,4 has a magnetic clapper 64secured thereto which cooperates with magnetic end members 66, 68 whichare respectively secured to frame portion 28 and which support the core70 for actuating coil 72. Actuating pawl 54 is biased into the positionshown in FIG. 4 by a suitable spring 74 having one end engaging end 76of actuating pawl 54 and its other end engaging spring hanger 78 whichis secured to crossbar 30. It will be seen that when the coil 72 isenergized, clapper 64 will be magnetically attracted toward members 66,68, thus causing the upstanding portion 58 to pivot against the forceexerted by spring 74 and causing end `80 of the yoke portion 60to engagestar wheel 42 to rotate the same and the lowest order number wheel 32through gears 44 and 50 and pinion 46 by onehalf digit. When coil 72 isdeenergized, spring 74 returns the actuating pawl 54 to the positionshown in FIG. 4 thus causing end 82 of the yoke portion 60 to engage thestar wheel 42 to advance the same and the lowest order number wheel 32an additional half digit. It will now be seen that one completeenergizing pulse applied to the actuating coil 72 will result inactuation of the star wheel 42 by the actuating pawl S4 to advance thesame and the lowest order number wheel 32 by one full digit.

Number wheels 32 and 34 are connected by conventional intermittentmotion transfer mechanism comprising a conventional two tooth gear andlocking cam 84 secured to number wheel 32, a conventional transferpinion 86 rotatably mounted on pinion shaft 48 and a full tooth gear 88secured to number wheel 34 and having heart-shaped cam 90 securedthereto. Likewise, number wheel 34 is connected to number wheel 36 bytwo-tooth gear and locking cam 92, transfer pinion 94 rotatably mountedon pinion shaft 48, and full-tooth gear 96, and number wheel 36 isconnected to number wheel 38 by two-tooth gear and locking cam 98,transfer pinion rotatably mounted on pinion shaft 48, and full-toothgear 102. yIn the illustrated embodiment, the full-tooth gears 88, 96and 102 are provided with twenty teeth and the transfer pinions 86, 94and 100 are provided with eight teeth meshing with the respectivefull-tooth gears and with every other tooth being removed in the portioncoopertaing with the respective two-tooth gear and locking cam.Heart-shaped cams 104 and 106 are respectively secured to the gears 96and 102 on the number wheels 36 and 38.

It will be readily understood that with the counter constructionillustrated, advance of each lower order number wheel through onecomplete revolution will result in incremental advance of the nexthigher order number wheel by 36, i.e., one digit. It will be furtherunderstood that the counter apparatus thus far described is conventionaland that other equivalent types of actuating and transferring mechanismscan be employed.

In order to provide for resetting the counter apparatus above-described,the mechanism now to be described is provided. An operating member 108is provided pivotally mounted on shaft 110 extending between frame ends22, 24, and having four resetting arms or shoes 112, 114, 116

and 118 extending upwardly therefrom and respectively` cooperating withthe heart-shaped cams 152, 90, 104, and 106 as will be hereinafterdescribed. Each of the reset shoes 112, 114, 116, 118 has a curvedsurface 120 formed 'asienta/1 at its outer end which terminates n anactuating corner 122, the surfaces 120 being outwardly curved or convexwith respect to the heart-shaped cams; the curvature of the surfaces 120of the illustrated embodiment will be more fully described hereinafter.

An actuating member 124 is provided mounted on shaft 110 and connectedto the operating member 108; in the illustrated embodiment theconnection of the actuating member 124 to the operating member 108 isprovided by a lost motion connection comprising a pin 126 on theoperating member 108 which extends through a slot 128 in the actuatingmember 124 and which is connected to another pin 130 on the actuatingmember 124 by a suitable spring 132. A segmental gear 134 is secured tothe actuating member 124 and meshes with another gear 136 mounted onshaft 138 which extends between the frame ends 22, 24. An actuatinglever 140 is secured to gear 136 in any suitable manner as by a pin 142and may have an actuating link 144 connected thereto.

Operating member 108 resetting shoes 112, 114, 116, and 118, actuatingmember 124, and gears 134, 136 are biased to a first or normal positionby means of a suitable spring 146 having one end connected to theoperating member 108 and its other end connected to frame end 24, asbest seen in FIG. 2. It will now be seen that actuation of actuatinglink 144 in the direction shown by the arrow 148 in FIG. 5 will causegears 136 and 134 to rotate actuating member 124, operating member 108and the resetting shoes 112, 114, 116, 118 in the direction shown by thearrow 150 in FIG. 5. Rotation of the resetting shoes results inengagement of the corners 122 with any of the heart-shaped cams whichare rotated away from their normal positions, thus causing rotation ofthe heart-shaped cams to their normal positions in which the curvedsurfaces 120 of the resetting shoes are in engagement with the lobes 152of the heartshaped cams which define the dwell portion thereof, as willbe hereinafter more fully described.

Pinion shaft 48 upon which pinions 46, 86, 94, and 100 are rotatablymounted is supported by a U-shaped bracket member 156 pivotally mountedby means of rod 158 extending between frame ends 22, 24. Bracket 156 isthus pivotally movable between a first position in which the pinions arein mesh with the respective gears and a second position in which thepinions are out of mesh with the gears. A resilient pinion positioningplate member 160y is provided secured to the crossbar 30 and having aplurality of resilient fingers 162, 164 and 166 extending therefrom.Resilient finger 162 is in alignment with pinion 46 and the mutilatedportion of pinion 86, finger 164 is in alignment with the mutilatedportion of pinion 94, and finger 166 is in alignment with the mutilatedportion of pinion 100. Finger 162 has a slot 168 formed therein whichaccommodates one tooth of pinion 46 so that alternate teeth of pinion 46engage finger 162 when the bracket 156 is pivoted downwardly to itssecond position. Recalling that alternate teeth are removed from themutilated portions of pinions 86, 94 and 100, the fingers 162, 164 and166 respectively engage the pinions 46, 86, 94, 100 when the bracketmember 156 is pivoted to its second position preventing the pinions fromrotating when out of 4mesh with the respective gears and properlypositioning the pini-ons so that they will go back into mesh with therespective gears when the bracket member 156 is returned to its firstposition.

Bracket member 156 is biased into its rst position with the pinionsrespectively in mesh with the gears by means of a suitable torsionspring 170 surrounding pivot rod 158 having one end engaging the pinionshaft 48` and its other end extending through and engaging a suitableopening in the crossbar 30. Adjustable member 172 is slidably mounted ina slot formed in the crossbar 30 and engages the bracket member 156 inits first position.

In order to pivot bracket member 156 from its first to its secondposition thereby moving the pinions out of mesh with the respectivegears in response to movement of the resetting shoes 112, 114, 116, and118 toward their second positions but in advance of engagement of thecorners 122 with the heart-shaped cams 52, 90, 104 and 106, and topermit the bracket member 156 to return to its first position thereby tore-engage the pinions with the respective gears while the surfaces ofthe reset shoes are still engaged with the lobes 152 of the heart-shapedcams, dog or lever member 174 is provided pivotally mounted on bracketmember 156 by a suitable .pin 176 for movement between first and secondpositions. Lever member 174 has a first end 178 which extends toward theactuating member 124 and a second end 180 with pivot pin 176 beingintermediate the two ends. Lever member 174 has an abutment portion 182which in the first position. of lever member 174 engages pivot rod 158`of the bracket member 156. Lever member 174 is biased into its firstposition with abutment 182 in engagement with pivot rod 158 by means ofa suitable coil spring 184 surrounding pivot pin 176 with one endthereof engaging pvot rod 158 and the other end engaging a suitableopening in end of lever member 174.

Referring now particularly to FIGS. 8 through 11, inclusive, it will beseen that actuating member 124 has .a cam 186 formed thereon. It willfurther be seen that the lever member or dog 174 is in its firstposition and that the bracket member 156 is also in its first positionwith the pinions in mesh with the respective gears when the end 178 ofthe lever member 174 is out of engagement with the cam 186, as seen inFIGS. 8 and l0. lIt will now be seen that when the actuating member 124is rotated by means of member 144, lever 140, and gears 134, 136 so asto rotate operating member 108` and resetting shoes 112, 114, 116 and118 in the direction shown by the arrow 150, the leading edge 188 of cam186 will engage end 178 of lever member 174 thus urging abutment 182against the pivot rod 158 and causing bracket member 156 to pivot fromits first position with the pinions respectively meshed with the gearsto its second position with the pinions out of mesh with theirrespective gears; the leading edge 188 of the Cam 186 is located so thatbracket member 156 is pivoted to move the pinions out of mesh with therespective gears prior to initial engagement of the corner 122 of therespective resetting shoes with any of the heart-shaped calms.

End 178 of lever 174 in the second or pivoted position of bracket member156 is in engagement with the high portion 190 of cam 186 thus retainingthe bracket member 156 in its second position with the pinions out ofmesh with their respective gears while the resetting shoes 112, 114, 116and 118 engage the heart-shaped cams and move the same to their neutralpositions. When the resetting shoes have reached their second positionswith their curved surfaces 120 engaging the lobes 152 of theheart-shaped cams, end 17 8 of the lever or dog member 174 reaches thetrailing edge 192 of the cam 186 thus permitting the bracket member 156to be returned to its first position under the iniluence of spring 170vand bringing the pinions back into mesh with their respective gears, itbeing observed, however, that the resetting shoes are still engaged withthe lobes 152 of the respective heartshaped cams thus restraining thecams and the respective number wheels against rotation.

When the `actuating force is removed from the member 144 so that theoperating member 108, the resetting shoes 112, 114, 116, 118, theactuating member 124 and gears 134, 136 are returned to their rstpositions in the direction shown by the arrow 192 in FIG. ll, end 178 oflever member 174 again engages the high portion 190 of the cam 186 whichpivots the lever member 174 to its second position with the bracketmember 156, however, remaining in its first position with the pinionsengaged with their respective gears, as best seen in FIG. l1. When theresetting shoes 112, 114, 116, 118 have been restored to their firstpositions as shown in FIG. 8, the end 178 of the lever member 174 hasmoved off of the high portion 190 of the cam 186 thus permitting theJever member 174 to be returned to its first position under the inuenceof spring 154.

It will now be seen that with the resetting mechanism as thus fardescribed, the pinions are moved out of mesh with the respective gearsin advance of movement of the resetting shoes into engagement with therespective heartshaped cams, and are retained out of mesh during theinterval in which the resetting shoes are rotated so as to rotate theheart-shaped cams .and the number wheels to their normal positions,Further, it is seen that at the end `of the initial resetting stroke,the pinions are permitted to move back into mesh with the respectivegears while the resetting shoes are still engaged with the dwellportions of the heart-shaped cams thus accurately positioning the numberwheels when the pinions are brought back into mesh with the respectivegears. Following the re-engagement of the pinions with the respectivegears, the resetting shoes are restored to their initial position withthe pinions remaining in mesh with the respective gears during thisreturn stroke.

Referring now to FlG. 12, it will now be seen that the `actuating corner122 of the resetting shoe 112 engages the surface of the heart-shapedcam 52 when the same is rotated away from its normal position, thecorner 122 rotating the heart-shaped cam toward its normal positionuntil a point adjacent thereto at which the arcuate surfa'ce 120 willengage the adjacent lobe 152. Further rotation of the heart-shaped calm52 toward its normal position is now accomplished by a camming orwedging action of the arcuate surface 120 with the adjacent lobe 152until the surface 120 engages both lobes at which point the heart-shapedcam 52 is now in its normal position and firmly restrained .againstfurther rotation.

The provision of surface 120 on the lresetting shoes 112 having -aradius of curvature exactly equal to the spacing between the axis 1110and the surfaces of the lobes 152, respecti-vely, as shown by thedimension line 208, is difficult due to the close tolerances which wouldbe required and for that reason it is preferred to form the arcuatesurface 120 with a radius of curvature 210 slightly greater than thespacing `from the axis 110 to the lobes 152, as indicated by the dottedline 212. This in turn provides a wedging action with the lobes 152which more firmly retains the heart-shaped cam 52 and its accompanyingnumber Wheel in the neutral position.

Referring again to FIGS. 8 through 11, the resetting shoes 112, 114, 116and 118 thus have the radius of curvature of their arcuate surfaces 120formed slightly greater than the spacing between the axis of shaft 110and the lobes 152 of the heart-shaped cams when in their nonmalpositions, the accompanying wedging action of the surfaces 120 of theresetting shoes being accommodated by the lost-motion connection betweenthe actuating member 124 and the operating member 108 provided by thepin 126, slot 128, pin 130, and spring i132, as best seen in FIG. l0.While the center of the radius of curvature of the arcuate surfaces 120of the resetting shoes 112, 114, 116 and 118 is desirably locatedcoincident with the axis of shaft 110, in the illustrated embodiment formanufacturing reasons the center of the radius of curvature of thearcuate surfaces 120 was actually located at point 214 slightly offsetfrom the axis of shaft 110, as shown in FIG. 8. Returning momentarily toFIG. 12, it will be seen that the center 214 of the radius of curvatureof the arcuate surfaces 120 of the reset shoes will rotate about theaxis of the shaft 110, as shown by the dotted line 216, this slighteccentricity actually enhancing the camming action of the surfaces 120with the heart-shaped cams and accentuating the above-referred towedging action.

It will be readily understood that the above-described lost-motionconnection between the actuating member 124 and the operating member 108may be eliminated and an adjustable connection between the two membersprovided by means of an adjusting screw 220` extending through the slot128 and received in a suitable tapped opening in the operating member108, as shown in `FIG. 13. In certain instances, the actuating member124 and operating member 108 may be rigidly connected, as by a screw222, as shown in FIG. 14, the Wedging action of the surfaces of theresetting shoes with the lobes 152 of the heart-shaped cams beingaccommodated by deflection of the shafts 40 and 110.

It will now be readily seen that by virtue of the camming action of thearcuate surfaces of the resetting shoes against the heart-shaped cams asthey approach their normal positions, less `force is required tocomplete restoration of the heart-shaped cams and numeral wheels totheir normal positions than was previously required in priorconventional reset counters employing reset shoes which exerted apushing force against the cams throughout their resetting motion.

While the invention has been illustrated and described as embodied in acounter of the impulse type in which there are only two discrete digitalpositions, i.e., numeral and half numeral, the improved resettingmechanism of the invention may equally advantageously be employed inconjunction with a continuously rotating-type counter construction ofthe type illustrated and described in Patent No. 3,050,250 to J. H.Mann, and assigned to the assignee of t-he present invention.

While I have illustrated and described a specific embodiment of myinvention, further modifications and improvements will occur to thoseskilled in the art and I desire therefore in the appended claims tocover all modifications which do not depart from the spirit and scope ofmy invention.

What is claimed is:

1. In a revolution counter of the reset type including a number wheelhaving a gear connected thereto and rotatable therewith and a pinionnormally in mesh with said gear, mechanism for returning said numberwheel to a predetermined rotational position from another positionrotationally spaced therefrom, said mechanism comprising: first cammeans connected to said number wheel and rotatable therewith, said firstcam means having high and dwell portions yand having a normal positionwhen said number wheel is in said predetermined position; an operatingmember movable between said first and second positions, said operatingmember in said first position vbeing out of engagement with said `firstcam means, said operating member being adapted to engage said first cammeans when the same is rotated away from said normal positionthereof'and to move the same to said normal position thereof responsivet-o movement of said operating member from said first to said secondpositions thereof, said operating member in said second position thereofengaging said dwell portion of said first cam means; a member rotatablymounting said pinion and movable between a first position with saidpinion in mesh with said gear and a second position with said pinion outof mesh with said gear; means for normally biasing said m-ounting memberto said first portion thereof; selectively actuable means connected tosaid operating member for moving the same between said first and secondpositions thereof; second cam means on said actuable means andcooperating cam follower means on said mounting member, said second cammeans and said cam follower means being proportioned and arranged tomove said mounting member from said first position toward said secondposition thereof responsive to movement of said operating member towardsaid second position thereof with said pinion moving out of mesh withsaid first gear in advance of engagement of said operating member withysaid first cam means, said second cam means and cam follower meansbeing proportioned `and arranged to permit said mounting member to moveto said first position thereof under the infiuence of said biasing meanswhen said operating member reaches said second position thereof, saidsecond cam means and cam follower means being proportioned and arrangedto retain said mounting member in said first position thereof duringm-ovement of said operating member from said second position to saidfirst position thereof whereby said pinion is moved into mes-h with saidgear prior to movement of said operating member out of engagement withsaid dwell portion of said first cam means.

2. The mechanism of claim 1 wherein said first cam means iseccentrically mounted on a first axis, and wherein said operating memberis mounted for rotation on a second axis spaced from and parallel withsaid first axis, said operating member having a surface integraltherewith which engages said dwell portion when said operating member isin said second position thereof, said surface being convexly curved withrespect to said first cam means.

3. The mechanism of claim 2 wherein said surface is generally arcuatewith the center of its radius of curvature located adjacent a linepassing through said axes.

4. The mechanism of claim 2 wherein said surface is generally arcuatewith the center of its radius of curvature located adjacent said secondaxis.

S. The mechanism of claim 1 wherein said first cam means iseccentrically mounted on a first axis coincident with the axis of saidgear and has a symmetrical heartshaped surface having a point definingsaid high portion and two lobes mutually defining said dwell portion,and wherein said operating member comprises a lever pivotally mounted ona second axis spaced from and parallel with said first axis, saidoperating member having a generally arcuate surface integrally formed onend end thereof which terminates in a corner, said corner initiallyengaging the surface of said first cam means when the same is rotatedaway from said normal position thereof, said arcuate surface engagingsaid lobes when said operating member is in said second condition, saidarcuate surface having the center of its radius of curvature locatedadjacent said second axis,

6. The mechanism of claim 5 wherein said radius of curvature of saidarcuate surface is slightly greater than the spacing between said secondaxis and said lobes, respectively, when said first cam means is in saidnormal position whereby said arcuate surface is wedged against saidlobes when said operating member is in said second position.

7. The mechanism of claim 1 wherein said first cam means iseccentrically mounted on said first axis, and wherein said operatingmember is mounted for rotation on a second axis spaced from and parallelwith said first axis, said operating member having an arcuate surfacewith the center of its radius of curvature located adjacent said secondaxis.

8. The mechanism of lclaim 1 wherein said first cam means iseccentrically mounted on a first axis coincident with the axis of saidgear and has a symmetrical heartshaped surface having a point definingsaid high portion and two lobes mutually defining said dwell portion,and wherein said operating member is mounted for rotation on a secondaxis spaced 4from and parallel with said first axis, said operatingmember having an arcuate surface with the center of its radius ofcurvature located adjacent said second axis, said arcuate surface ofsaid operating member terminating in a corner, said corner initiallyengaging the surface of said first cam means when the same is` rotatedaway from the normal position thereof, said arcuate surface engagingsaid lobes when said operating member is in said second positionthereof.

9. The mechanism of claim 8 wherein the largest diametral distancebetween said second axis and said arcuate surface is slightly greaterthan the spacing betweensaid second axis and said lobes, respectively,when said first cam means is in said normal position whereby saidarcuate surface is wedged against said lobes when said operating memberis in said second position.

10. In a revolution counter of the reset type comprising coaxial lowerand higher order number wheels, and transfer means for rotating thehigher order number wheel a predetermined incremental amount in responseto a predetermined rotation of the lower order number wheel, saidtransfer means .including a segmental gear coaxially secured to thelower order number wheel, a full-tooth gear coaxially secured to thehigher order number wheel, and a transfer pinion normally meshing withsaid gears, mechanism for resetting said number wheels to predeterminedrotational position-s comprising: first and second cam meansrespectively connected to said lower and higher order number wheels androtatable therewith, each of said cam means having high and dwellportions and having a normal position when the respective number Wheelis in said predetermined position; operating means movable between firstand second postions, said operating means in said first position beingout of engagement with both of said cam means, said operating meansbeing adapted respectively to engage both of said cam means when thesame are rotated away from said normal positions thereof and to move thesame to said normal positions thereof responsive to movement of saidoperating means from said first to said second positions thereof, saidoperating means in said second position thereof respectively engagingsaid dwell portion of both of said cam means; means rotatably mountingsaid pinion and movable between a first position with said pinion inmesh with said gears and a second position with said pinion out of meshtherewith; means for normally biasing said mounting means to said firstportion thereof; selectively actuable means connected to said operatingmeans for moving the same between said first and second positionsthereof; third cam means on said actuable means and c0- operating camfollower means on said mounting means, said third cam means and camfollower means being prol portioned and arranged to move said mountingmeans to said second position thereof `in response to movement of saidoperating means toward said second position thereof with said pinionmoving out of mesh with said gears in advance of engagement of saidoperating means with said first and second cam means, respectively, saidthird cam means and cam follower means being proportioned and arrangedto permit said mounting means to move to said first position thereofunder the influence of said biasing means when said operating meansreaches said second position and to retain said mounting means in saidfirst position thereof when said operating means is moved from saidsecond to said first position thereof whereby said pinion is moved intomesh with said gears prior to movement of said operating means out ofengagement with said dwell portions of both of said cam means.

11. The mechanism of claim l()` further comprising second means fornormally biasing said operating means to said first position thereof;and wherein said third cam means has a high portion with opposite endsthereof joined to a dwell portion; said cam lfollower means comprising alever pivotally mounted on said mounting means for movement between saidfirst and second positions, abutment means engaged by said lever in saidfirst position thereof, and means n-ormally `biasing said lever to saidfirst position thereof; said lever cooperating with said third cam meansand being in said first position thereof when not engaged with said highportion thereof; said high portion of said third cam means engaging saidlever and urging the same against said abutment means thereby movingsaid mounting means to said second position thereof when saidselectively actuable means is moved to move said operating means towardsaid second position thereof, said lever moving off of said high portionof said third cam means when said selectively actuable means is moved tomove said operating means to said second position thereof therebypermitting said firstnamed biasing means -to move said mounting means to1 1 said first position thereof, said high portion of said third cammeans engaging said lever and moving the same to 'said second positionthereof when said selectively actuable means is moved to move saidoperating means from said second to said first position thereof.

12. The mechanism of claim 11 wherein said first and second cam meansare respectively eccentrically coaxially mounted on said number iwheels,each of said first and second cam means having a symmetricalheart-shaped surface having a point defining said high portion and twolobes mutually defining said dwell portion; said operating meanscomprising a pair of members mounted for rotation on a second axisspaced from and parallel with the axis of said number wheels, each ofsaid members having a surface cooperating with the respective cam meanssurface and engaging the lobes thereof when said operating means is insaid second position, said surfaces of each of said members beinggenerally arcuate with the center of the radius of curvature thereoflocated adjacent a line passing through said axes; said selectivelyactuable means comprising a member coaxially mounted on said second axishaving said third cam means formed thereon; said mounting meanscomprising a member pivotally mounted on a third axis respectivelyspaced from said second axis and the axis of said number wheels andparallel therewith.

13. In a revolution counter of the reset type comprising coaxial lowerand higher order number wheels, and transfer means for rotating thehigher order number wheel a predetermined incremental amount in responseto a predetermined rotation of the lower order number wheel, saidtransfer means including a segmental gear coaxially secured to the lowerorder number wheel, a fulltooth gear coaxially secured to the higherorder number wheel, and a transfer pinion normally meshing with saidgears, mechanism for resetting said number wheels to predeterminedrotational positions comprising: first and second symmetricalheart-shaped cams respectively eccentrically coaxially secured to saidnumber Iwheels, each of said cams having a point dening a high portionland a pair of lobes defining a dwell portion and having a normalposition when the respective number wheel is in its predeterminedposition; an operating member pivotally mounted on a second axis spacedfrom and parallel with the axis of said number wheels for movementbetween first and second positions; said operating -member having a pairof arms respectively extending therefrom, each of said arms having agenerally arcuate end which terminates in a corner, said cornersengaging respective cams when the same are rotated away from said normalpositions thereof as said operating member is moved from said first tosaid second position thereof thereby to move said cams to said normalpositions, said arcuate ends engaging the lobes of the respective camswhen the same are in said normal position thereof and said operatingmember is in said second position thereof, each of said arcuate endshaving the center of its radius of curvature located adjacent saidsecond axis; spring means normally biasing said operating member to saidfirst position thereof; a pinion `carrier rotatably mounting said pinionand pivotally mounted on a third axis spaced from said second axis andthe axis of said number wheels and parallel therewith yfor movementbetween a first position with said pinion in mesh with said gears and asecond position with said pinion out of mesh with said gears; springmeans normally biasing said pinion carrier to said first positionthereof; an actuating member rotatably mounted on said second axis andconnected to said operating member for selectively moving said operatingmember between said first and second positions thereof, said actuatingmember having a third cam formed thereon and having a high portion withopposite ends thereof joined to a dwell portion; a lever memberpivotally mounted intermediate its ends on said pinion carrier formovement between first and second positions; abutment means engaged byone end of said lever member in said first position thereof; a springnormally biasing said lever member to said first position thereof; theother end of said lever cooperating with said third cam and being insaid first position thereof when not engaged by the high portion ofIsaid third cam; said high portion of said third cam engaging said otherend of said lever member and urging said one end thereof against saidabutment means thereby moving said pinion carrier to said secondposition thereof when said actuating member is moved to move saidoperating member away from said first position toward said secondposition thereof whereby said pinion is moved out of mesh with saidgears in advance of engagement of said corners with the respective firstand second cams, said other end of said lever moving off of said highportion of said third cam when said actuating member is moved to movesaid operating member to said second position thereof whereby saidpinion carrier is moved to said first position thereof, said highportion of said third cam engaging said other end of said lever memberand moving the same to said second position thereof when said actuatingmember is moved to move said operating member from said second to saidfirst position thereof whereby said pinion carrier remains in said firstposition thereof.

14. The mechanism of claim 13 wherein the radius of curvature of saidarcuate end of each of said arms is slightly greater than the spacingbetween said second axis andthe lobes -of said first and second cams,respectively, whenv in said normal positions thereof whereby saidarcuate ends of said arms are respectively wedged against the lobes ofsaid first and second cams 'when said operating member is in said secondposition thereof.

15. T-he mechanism of claim 14 wherein said actuating member isconnected to said operating member by a lostmotion connection foraccommodating said wedging of said arcuate ends of said arms against thelobes of said rst and second cams.

16. In a revolution counter of the reset type comprising coaxial lowerand higher order number wheels, and transfer means for rotating thehigher order number wheel ia predetermined incremental amount inresponse to a predetermined rotation of the lower order number wheel,mechanism for resetting said number wheels to predetermined rotationalpositions comprising: first and second cam means respectively connectedto said lower and higher order number wheels and rotatable therewith,each of .said cam means having high and dwell portions and having anormal position when the respective number wheel is in saidpredetermined position; and operating means mounted for rotation betweenfirst and second positions about a second axis spaced from the axis ofsaid number wheels and parallel therewith, said operating meansrespectively having surfaces which are convexly curved with respect tosaid cam means and lwhich respectively terminate in a corner, saidcorners respectively cooperatively engaging said high portions of saidcam means when the same are rotated away from said normal positionsthereof and exerting a pushing force thereon thereby to rotate the sametoward said normal positions thereof in response to initial rotation ofsaid operating means away from said `first position toward said secondposition thereof, said curved surfaces of said operating meansrespectively cooperatively engaging said cam means and exerting acamming action thereon thereby further to rotate the same toward saidnormal positions thereof in response to further rotation of saidoperating means toward said second position thereof, said curvedsurfaces of said operating means in said second positions thereofrespectively engaging said dwell portions of said cam means in saidnormal positions thereof.

17. The mechanism of claim 1.6 wherein each of said surfaces isgenerally arcuate with the center of its radius of curvature locatedadjacent a line passing through said second axis and the axis of saidnumber wheels.

18. The mechanism of claim 16 wherein each of said surfaces is generallyarcuate with the center of its radius Iof curvature located adjacentsaid second axis.

19. The mechanism of claim 16 wherein each of said surfaces is generallyarcuate with the center of its radius of curvature located adjacent aline passing through said second axis and the axis of said numberwheels, said radius of curvature being slightly greater than the spacingbetween said second axis and said dwell portions of said cam means,respectively, lwhen said cam means are in said normal positions thereofwhereby said arcuate surfaces are respectively wedged against said dwellportions when said operating means is in said second position thereof.

20. In a revolution counter of the reset type including a number wheelhaving a gear connected thereto and rotatable therewith and a pinionnormally in mesh with said gear, mechanism for resetting said numberwheel to a predetermined rotational position comprising: a heartshapedcam connected to said number wheel and rotatable therewith, said camhaving a high point and two lobes mutually dening a dwell portion andhaving a normal position when said number wheel is in said predeterminedposition; operating means including a reset shoe mounted for pivotalmovement between first and second positions, said shoe being out ofengagement with said cam when said shoe is in said first positionthereof, said shoe being adapted to engage said cam when the same isaway from said normal position thereof and to move the same to saidnormal position responsive to movement of said shoe from said lirst tosaid second position thereof,

said shoe in said second position thereof engaging both -of said lobesand restraining said cam against rotation; means rotatably mounting saidpinion lfor pivotal movement -between a rst position in mesh with saidgear and a second position out of mesh therewith; means normally biasingsaid mounting means to said rst position thereof; said openating meansincluding actuating means connected thereto for selectively moving saidshoe 4between said iirst and second positions thereof; and cooperatingcam means on said operating means and mounting means proportioned andarranged to move said mounting means to said second position thereof inresponse to movement of said shoe toward said second position thereofbut in advance of engagement of said shoe with said cam whereby saidpinion is moved out of engagement with said gear in advance of saidengagement to permit said mounting means to return to said iirstposition thereof under the influence of said biasing means when saidshoe is in said second position whereby said pinion is returned to meshwith said gear while said cam is restrained by said shoe, and to retainsaid mounting means in said first position thereof with said pinion inmesh with said gear when said shoe is moved from said second to said rstposition thereof.

References Cited by the Examiner UNITED STATES PATENTS 3,178,111-r4/1965 Auer 23S-144 RICHARD B. WILKINSON, Primary Examiner.

1. IN A REVOLUTION COUNTER OF THE RESET TYPE INCLUDING A NUMBER WHEELHAVING A GEAR CONNECTED THERETO AND ROTATABLE THEREWITH AND A PINIONNORMALLY IN MESH WITH SAID GEAR, MECHANISM FOR RETURNING SAID NUMBERWHEEL TO A PREDETERMINED ROTATIONAL POSITION FROM ANOTHER POSITIONROTATIONALLY SPACED THEREFROM, SAID MECHANISM COMPRISING: FIRST CAMMEANS CONNECTED TO SAID NUMBER WHEEL AND ROTATABLE THEREWITH, SAID FIRSTCAM MEANS HAVING HIGH AND DWELL PORTIONS AND HAVING A NORMAL POSITIONWHEN SAID NUMBER WHEEL IS IN SAID PREDETERMINED POSITION; AN OPERATINGMEMBER MOVABLE BETWEEN SAID FIRST AND SECOND POSITIONS, SAID OPERATINGMEMBER IN SAID FIRST POSITION BEING OUT OF ENGAGEMENT WITH SAID FIRSTCAM MEANS, SAID OPERATING MEMBER BEING ADAPTED TO ENGAGE SAID FIRST CAMMEANS WHEN THE SAME IS ROTATED AWAY FROM SAID NORMAL POSITION THEREOFAND TO MOVE THE SAME TO SAID NORMAL POSITION THEREOF RESPONSIVE TOMOVEMENT OF SAID OPERATING MEMBER FROM SAID FIRST TO SAID SECONDPOSITIONS THEREOF, SAID OPERATING MEMBER IN SAID SECOND POSITION THEREOFENGAGING SAID DWELL PORTION OF SAID FIRST CAM MEANS; A MEMBER ROTATABLYMOUNTING SAID PINION AND MOVABLE BETWEEN A FIRST POSITION WITH SAIDPINION IN MESH WITH SAID GEAR AND A SECOND POSITION WITH SAID PINION OUTOF MESH WITH SAID GEAR; MEANS FOR NORMALLY BIASING SAID MOUNTING MEMBERTO SAID FIRST PORTION THEREOF; SELECTIVELY ACTUABLE MEANS CONNECTED TOSAID OPERATING MEMBER FOR MOVING THE SAME BETWEEN SAID FIRST AND SECONDPOSITIONS THEREOF; SECOND CAM MEANS ON SAID ACTUABLE MEANS ANDCOOPERATING CAM FOLLOWER MEANS ON SAID MOUNTING MEMBER, SAID SECOND CAMMEANS AND SAID CAM FOLLOWER MEANS BEING PROPORTIONED AND ARRANGED TOMOVE SAID MOUNTING MEMBER FROM SAID FIRST POSITION TOWARD SAID SECONDPOSITION THEREOF RESPONSIVE TO MOVEMENT OF SAID OPERATING MEMBER TOWARDSAID SECOND POSITION THEREOF WITH SAID PINION MOVING OUT OF MESH WITHSAID FIRST GEAR IN ADVANCE OF ENGAGEMENT OF SAID OPERATING MEMBER WITHSAID FIRST CAM MEANS, SAID SECOND CAM MEANS AND CAM FOLLOWER MEANS BEINGPROPORTIONED AND ARRANGED TO PERMIT SAID MOUNTING MEMBER TO MOVE TO SAIDFIRST POSITION THEREOF UNDER THE INFLUENCE OF SAID BIASING MEANS WHENSAID OPERATING MEMBER REACHES SAID SECOND POSITION THEREOF, SAID SECONDCAM MEANS AND CAM FOLLOWER MEANS BEING PROPORTIONED AND ARRANGED TORETAIN SAID MOUNTING MEMBER IN SAID FIRST POSITION THEREOF DURINGMOVEMENT OF SAID OPERATING MEMBER FROM SAID SECOND POSITION TO SAIDFIRST POSITION THEREOF WHEREBY SAID PINION IS MOVED INTO MESH WITH SAIDGEAR PRIOR TO MOVEMENT OF SAID OPERATING MEMBER OUT OF ENGAGEMENT WITHSAID DWELL PORTION OF SAID FIRST CAM MEANS.